Scheme for communication and transmitting discovery signal in mobile communication system

ABSTRACT

A method for performing communication by a first communication device in a mobile communication system is provided. The method includes determining whether the first communication device is proximate to a nearby second communication device through a short-range communication link, enabling one of a first long-range communication link with a network or the short-range communication link with the second communication device based on the determination as to whether the first communication device is proximate to the second communication device, and receiving data from the network through the enabled one of the first long-range communication link with the network or the short-range communication link.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of prior application Ser.No. 14/863,707, filed on Sep. 24, 2015, which will issue as U.S. Pat.No. 9,602,999 on Mar. 21, 2017 and claimed the benefit under 35 U.S.C. §119(a) of a Korean patent application filed on Oct. 1, 2014 in theKorean Intellectual Property Office and assigned Serial number10-2014-0132510, the entire disclosure of each of which is herebyincorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a method for changing communicationmodes and transmitting a discovery signal in a mobile communicationsystem. More particularly, the present disclosure relates to a methodfor establishing a mobile communication link based on a wearablecommunication device and a method for transmitting a discovery signalbased on call transmission.

BACKGROUND

As electronic devices are highly integrated and the application ofwireless communication techniques becomes more common, wristwatch- orglasses-like wearable electronic devices are coming to market.

Wearable electronic devices benefit over typical cellular phones orsmartphones for a portability perspective, and vice versa when it comesto communication performance and battery life.

If a wearable electronic device comes with cellular communicationcapability, the user who carries both the wearable device and a cellularphone ends up with two cellular communication-enabled devices.

As the case may be, the user may carry both or either of them. Theuser's demand to receive a service through cellular communications maybe met once he is served with his desired service from either thewearable device or cellular phone. Accordingly, there is a need for amethod that enables the user carrying one or more devices to managelong-range communication (e.g., cellular communication or Internetcommunication via Wi-Fi) and short-range communication (e.g., Bluetoothcommunication) of the devices, allowing for efficient use of hardwareand communication resources and increased user convenience.

Further, a need also exists for a method for automatically transmittingout a discovery signal to inform the surroundings of the position orcircumstance of the communication devices when the user cannot freelymanipulate the communication devices, e.g., when the user is in anemergency.

The above information is presented as background information only toassist with an understanding of the present disclosure. No determinationhas been made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the present disclosure.

SUMMARY

Aspects of the present disclosure are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentdisclosure is to provide a method for managing cellular communicationlinks of two or more communication devices and communication linksbetween the communication devices when the user carries thecommunication devices.

Another aspect of the present disclosure is to provide a method forefficiently managing cellular communication links and receiving datawhen the user carries both a smartphone and a wearable communicationdevice.

Another aspect of the present disclosure is to provide a method thatallows a communication device with no cellular communication means orwith the cellular communication of the communication device temporarilydisabled to directly perform long-range communication via a short-rangecommunication link.

Another aspect of the present disclosure is to provide a method forautomatically transmitting a discovery signal under a particularcircumstance by the user's manipulation or a particular operation of acommunication device.

In accordance with an aspect of the present disclosure, a method forperforming communication by a first communication device in a mobilecommunication system is provided. The method includes determiningwhether the first communication device is proximate to a nearby secondcommunication device through a short-range communication link, enablingone of a first long-range communication link with a network or theshort-range communication link with the second communication devicebased on the determination as to whether the first communication deviceis proximate to the second communication device, and receiving data fromthe network through the enabled one of the first long-rangecommunication link with the network or the short-range communicationlink.

In accordance with another aspect of the present disclosure, a firstcommunication device in a mobile communication system is provided. Thefirst communication device includes a controller configured to determinewhether the first communication device is proximate to a nearby secondcommunication device through a short-range communication link, to enableone of a first long-range communication link with a network or theshort-range communication link with the second communication devicebased on the determination as to whether the first communication deviceis proximate to the second communication device, and to receive datafrom the network through the enabled one of the first long-rangecommunication link with the network or the short-range communicationlink, and a communication unit configured to communicate data throughthe long-range communication link or the short-range communication linkunder the control of the controller.

In accordance with another aspect of the present disclosure, a methodfor transmitting a discovery signal by a communication device isprovided. The method includes triggering any one of a call dispatch, auser data transmission, and an application execution, determiningwhether any one of a destination phone number of the call, a destinationaddress of the user data, and the application is included in previouslystored information, determining whether there is a radio resource fordiscovery signal transmission, and transmitting the discovery signalbased on a result of the determination that there is a radio resourcefor discovery signal transmission.

In accordance with another aspect of the present disclosure, acommunication device for transmitting a discovery signal is provided.The apparatus includes a controller configured to trigger any one of acall dispatch, a user data transmission, and an application execution,to determine whether any one of a destination phone number of the call,a destination address of the user data, and the application is includedin previously stored information, to determine whether there is a radioresource for discovery signal transmission, and to transmit thediscovery signal based on a result of the determination that there is aradio resource for discovery signal transmission, and a communicationunit configured to communicate the discovery signal under the control ofthe controller.

In accordance with another aspect of the present disclosure, acommunication method by a first communication device in a mobilecommunication system is provided. The method includes transmitting arequest for long-range communication support information to a nearbysecond communication device through a short-range communication link,receiving the long-range communication support information from thesecond communication device, and accessing an Internet network throughthe short-range communication link using the long-range communicationsupport information, wherein the long-range communication supportinformation includes at least one of Wi-Fi Access Point (AP) accessinformation and long-term evolution (LTE) access information.

In accordance with another aspect of the present disclosure, a firstcommunication device in a mobile communication system is provided. Thefirst communication device includes a controller configured to transmita request for long-range communication support information to a nearbysecond communication device through a short-range communication link, toreceive the long-range communication support information from the secondcommunication device, and to access an Internet network through theshort-range communication link using the long-range communicationsupport information, and a communication device configured tocommunicate data through the short-range communication link under thecontrol of the controller, wherein the long-range communication supportinformation includes at least one of Wi-Fi AP access information and LTEaccess information.

The cellular communication and inter-device communication of one or moredevices carried by the user may be managed, thus leading to efficientuse of hardware and communication resources of the devices along withincreased user convenience.

A communication device equipped with a short-range communication meansalone may directly perform long-range communication with the aid of anearby communication device.

Under the circumstance that it is difficult to expect the user'smanipulation, e.g., in an emergency, a discovery signal may beautomatically transmitted out from the user's communication device bycall dispatch or data transmission by the user, and discovery signaltransmission considering the resources of the communication device ispossible.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the present disclosure will be more apparent from thefollowing description taken in conjunction with the accompanyingdrawings, in wherein:

FIG. 1 illustrates a connectivity group including one or morecommunication devices according to a first embodiment of the presentdisclosure;

FIG. 2 illustrates a method in which a communication devices in apersonal connectivity group (PCG) determine a communication device tooperate as a connectivity controller (CC) according to a firstembodiment of the present disclosure;

FIG. 3 illustrates a method in which a communication devices in a PCGdetermine a communication device to operate as a connectivity enabler(CE) according to a first embodiment of the present disclosure;

FIG. 4 illustrates a communication path to a cellular network, of a userwith a smartphone and a wearable communication device according to afirst embodiment of the present disclosure;

FIGS. 5A, 5B, and 5C illustrate a method in which two communicationdevices configure communication links with a network based on proximityaccording to a first embodiment of the present disclosure;

FIG. 6 illustrates a long-range communication method by a communicationdevice according to a second embodiment of the present disclosure;

FIG. 7 illustrates a procedure in which a communication device (UE)communicates with a base station and a ProSe function to transmit adiscovery signal according to a third embodiment of the presentdisclosure;

FIG. 8 illustrates a discovery signal transmission operation by acommunication device according to a third embodiment of the presentdisclosure; and

FIG. 9 illustrates a configuration of a communication device accordingto an embodiment of the present disclosure.

Throughout the drawings, like reference numerals will be understood torefer to like parts, components, and structures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the present disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thepresent disclosure. In addition, descriptions of well-known functionsand constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of the presentdisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of the presentdisclosure is provided for illustration purpose only and not for thepurpose of limiting the present disclosure as defined by the appendedclaims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

Before detailing the present disclosure, some terms as used herein maybe interpreted as follows, for example. However, it should be noted thatthe present disclosure is not limited thereto.

In an embodiment of the present disclosure, a network (NW) is an entitycommunicating with a device and may be a base station (ST) over thenetwork. Accordingly, the network may also be denoted a NodeB (NB),eNodeB (eNB), or access point (AP).

In an embodiment of the present disclosure, a proximity service function(ProSe) function is an entity over a network supportive of a discoveryfunction of a communication device and may be a different entity from abase station or may be the same entity as a base station (when the ProSefunction is implemented in the base station). The ProSe function mayalso be referred to as a device-to-device (D2D) function. In anembodiment of the present disclosure, D2D is the same in meaning asProSe, and D2D and ProSe may be interchangeably used.

In an embodiment of the present disclosure, a communication device is anentity communicating with a network or other nearby communicationdevice, and the communication device may be a cellular phone or awearable communication device. The communication device may also bedenoted a device, user equipment (UE), mobile station (MS), mobileequipment (ME), or terminal.

In an embodiment of the present disclosure, a wearable communicationdevice means a communication device (e.g., a smartwatch, an armband,smart glasses, a smart contact lens, and the like) that may be worn orinserted by the user on his particular body part (e.g., his wrist, arm,head, or eyeball). More particularly, the term “communication device” asused herein is used to collectively refer to communication devices thatare not the typical wireless phone style communication devices.Accordingly, in an embodiment of the present disclosure, a pen-shapedcommunication device, e.g., a smart pen, may also be denoted a wearablecommunication device. In this present disclosure, a wearablecommunication device may also be called a wearable device. For example,a smartwatch may be a commercial product, such as Galaxy Gear′, andsmart glasses may be a commercial product, such as Google Glass™.

Now described are a first embodiment of a method in which acommunication device determines a communication mode using a proximitydegree and performs long-range communications, a second embodiment of amethod in which a communication device, which may perform onlyshort-range communication with the aid of other communication deviceperforming long-range communication, directly performs long-rangecommunication, and a third embodiment of a method in which acommunication device transmits a discovery signal.

First, as the first embodiment of the present disclosure, an embodimentis described in which communication modes are changed based on aproximity degree between two or more communication devices.

FIG. 1 illustrates a connectivity group including one or morecommunication devices according to a first embodiment of the presentdisclosure.

Referring to FIG. 1, the user may be served with a communication servicefrom a cellular network by carrying one or more communication devicesthat may perform long-range communication, wide area network (WAN)communication, such as long term evolution (LTE), universal mobiletelecommunication system (UMTS), and web real time communication(WebRTC).

The one or more communication devices that may perform long-rangecommunication may perform D2D communication with the other communicationdevice through a short-range communication (SRC) link 110 and may form apersonal connectivity group (PCG) 100 through the short-rangecommunication link 110. The PCG is a group of communication devices thatmay be considered as being used by the user or as belonging, and all orsome of the communication devices may perform long-range communication,such as a WAN connection. The PCG may be classified as the same PCG withthe same indicator. For example, the communication devices may beidentified as being to the same PCG using the same indicator. The PCG100 may include at least one of, e.g., a cellular phone 102, asmartwatch 104, smart glasses 106, and a smart pen 108. The short-rangecommunication link may be a direct communication link established amongall the communication devices in the PGC 100 and may be implementedthrough a communication technique, such as, e.g., Bluetooth, Wi-FiDirect, or ZigBee. The short-range communication link may be formed in aone-to-one or one-to-n manner.

The PCG of FIG. 1 may be called a peer device group (PDG), and the PDGis described below in connection with the second embodiment.

The PCG 100 may include a communication device serving as a connectivitycontroller (CC) 104 controlling D2D connection and connection with thecellular network and a communication device serving as a connectivityenabler (CE) 102 performing cellular communication with the cellularnetwork.

The CC 104 is a device selecting and managing the CE 102. The CE 102 isa device in charge of inter-network (120) connection (or communication)with the devices belonging to the PCG 100 using a WAN communicationtechnique-based long-range communication (LRC) link 112. Somecommunication devices 104, 106, and 108 in the PCG 100 may communicatewith a network 120 by communicating through the short-rangecommunication link 110 with the CE 102 that is linked with the network120 through the long-range communication link 112. For example, the CE102 may operate as a data communication hub between the network 120 andthe communication devices in the PCG 100. In some cases, onecommunication device may serve as both the CC and the CE, and there maybe two or more communication devices serving as the CE in one PCG.

Any communication device in the PCG 100 may serve as the CC or CE.Although FIG. 1 illustrates an example where the smartwatch 104 is theCC, and the cellular phone 102 is the CC, other communication device maybe the CC or CE. Further, the CC and the CE may be the samecommunication device.

The determination (i.e., the role determination) as to whichcommunication device is supposed to play a role as the CC or CE may beperformed by the operation of each communication device in the PCG. Inthis case, the operation for the role determination may be conductedbased on some rule that is shared by the communication devices in thePCG.

The rule for the role determination may be defined using at least one ofa certain order of priority, whether the user carries the communicationdevice, and information on remaining battery life. The order of prioritymay be managed by one or both of the CC and the CE. The order ofpriority may be set and stored as a particular value of a form that maybe recognized by the communication devices in the PCG. The order ofpriority may be stored in the form of a priority list of thecommunication devices in the PCG. When multiple PCGs are there in thenetwork, the priority list of each PCG may be shared between themultiple PCGs. Further, the priority list for one PCG may be shared inthe PCG between the communication devices belonging to the PCG.

When the user carries a smartphone, a smartwatch, and smart glasses, theorder of priority for serving as the CC may be determined, e.g., in theorder of smartwatch>smart glasses>smartphone. The reason why thesmartwatch has the highest priority in playing a role as the CC is thatthe smartwatch is highly likely to be with the user for most of the timeand that there is little chance of a change in CC role to othercommunication device.

Further, in the above case, the order of priority for serving as the CEmay be determined, e.g., in the order of smartphone>smartwatch>smartglasses. The reason why the smartphone has the highest priority inplaying a role as the CE is that the smartphone carries better hardwareresources and battery power as compared with the other communicationdevices and that there is little chance of a change in CE role to othercommunication device. The order of priority for serving as the CE may bevaried by the information on the remaining battery life reported by eachcommunication device to the CC. For example, when the smartwatch reportsthat the remaining battery life of the smartwatch is less than 10%, thesmartwatch and the smart glasses may be changed in order of priority.

TABLE 1 Communication device carried by user CC CE smartphone,smartwatch, smart glasses smartwatch smartphone smartphone, smartwatchsmartwatch smartphone smartphone, smart glasses smart glasses smartphonesmartwatch, smart glasses smartwatch smartwatch smartphone smartphonesmartphone smartwatch smartwatch smartwatch smart glasses smart glassessmart glasses

Table 1 shows examples of the CC and the CE determined according to therule obtained by combining the order of priority between devices andwhether the user carries the communication device.

When the user carries all of the smartphone, the smartwatch, and thesmart glasses, the smartwatch, which has the highest priority for theCC, and the smartphone, which has the highest priority for the CE, maybe determined as the CC and the CE, respectively. However, unless amongthe communication devices the communication devices with the highestpriority are worn, the communication devices with the next highestpriority would be determined as the CC and the CE, respectively.Meanwhile, when only one communication device is present, thecommunication device may be determined to play a role as the CC and theCE.

First described is a method in which the communication devices in thePCG determine a communication device to operate as the CC.

FIG. 2 illustrates a method in which a communication devices in a PCGdetermine a communication device to operate as a CC according to a firstembodiment of the present disclosure.

Referring to FIG. 2, when the PCG does not have a communication devicecapable of playing a role as the CC, each communication device maydetermine whether the communication device is supposed to be the CCdepending on the order of priority of the communication device andwhether the communication device is being worn by the user.

Each communication device in the PCG determines if the communicationdevice has the highest priority in the PCG in operation 200. If havingthe highest priority, the communication device may determine whether thecommunication device is being worn by the user in operation 202. Uponmeeting the two conditions of having the highest priority in the PCG andbeing worn by the user, the communication device may determine thecommunication device to be the CC in operation 204. Selectively, thecommunication device may transmit a control message to ambientcommunication devices to inform them that the communication device is tooperate as the CC in operation 206.

For example, the smartwatch with the highest priority may determinewhether the smartwatch is to play a role as the CC by determiningwhether the smartwatch is being worn by the user. When the smartwatch isdetermined to be being worn by the user, the smartwatch may determinethe smartwatch to be the CC and may inform the presence of thesmartwatch to the other communication devices in the PCG by transmittinga control message to the other communication devices to report that thesmartwatch is to operate as the CC. When the smartwatch is determinednot to be being worn by the user, the smartwatch might not determine thesmartwatch to be the CC. Selectively, when the smartwatch is determinednot to be being worn by the user, the smartwatch may transmit a controlmessage to inform that the smartwatch is not being worn by the user inorder to aid the other communication devices in determining whether theyare to play a role as the CC.

For the reason that there is no smartwatch in the PCG or the user doesnot wear the smartwatch, there might be no communication device to playa role as the CC in the PCG. In this case, the smart glasses with thenext highest priority may determine whether the smart glasses are toplay a role as the CC by determining whether the smart glasses are beingworn by the user. When the smart glasses are determined to be being wornby the user, the smart glasses may determine the smart glasses to be theCC and may inform the presence of the smart glasses in the PCG to theother communication devices by transmitting any control message to theother communication devices. When the smart glasses are determined notto be being worn by the user, the smart glasses might not determine thesmart glasses to be the CC. Selectively, when the smart glasses aredetermined not to be being worn by the user, the smart glasses maytransmit a control message to inform that the smart glasses are notbeing worn by the user in order to aid the other communication devicesin determining whether they are to play a role as the CC.

Now described is a method in which the communication devices in the PCGdetermine a communication device to operate as the CE.

FIG. 3 illustrates a method in which the communication devices in a PCGdetermine a communication device to operate as a CE according to a firstembodiment of the present disclosure.

Referring to FIG. 3, when there is no communication device, in the PCG,to play a role as the CE, the CC searches for ambient PCG communicationdevices using the short-range communication link in operation 300. TheCC may determine the device with the highest priority to play a role asthe CE among the searched communication devices as the CE in operation302. In this case, the CC may transmit a control message to thecommunication device determined as the CE to instruct the determinedcommunication device to operate as the CE. For example, the controlmessage for instructing to operate as the CE is a control messagetransmitted by the CC to instruct the CE to enable a long-rangecommunication (LRC) link.

In the operation 302 to determine the communication device to operate asthe CE, whether the communication device is being worn by the user maybe reflected. Unless the communication device determined as the CE isbeing worn by the user, the communication device determined as the CEmay respond to the CC with a message indicating that the communicationdevice cannot operate as the CE in operation 304. In this case, the CCremoves the communication device having responded with the message fromCE candidates in operation 306 and will newly determine a communicationdevice to operate as the CE.

For example, the smartwatch playing a role as the CC identifies throughthe short-range communication link whether a smartphone is present inthe PCG. If it is identified that there is a smartphone in the PCG, theCC may transmit, through the short-range communication link to thesmartphone, a control message to instruct the smartphone to operate asthe CE.

Selectively, upon reception of the control message, the smartphone maydetermine whether the smartphone is being carried by the user. Ifdetermined to be being carried by the user, the smartphone may transmit,to the CC, a message to inform that the smartphone accepts the CE roleand may operate as the CE. The smartphone operating as the CE mayprovide a connection with an external network through a long-rangecommunication link. Meanwhile, if determined not to be being carried bythe user, the smartphone may transmit, to the CC, a message to informthat the smartphone cannot operate as the CE.

Selectively, if the determination of a communication device to operateas the CE is complete, the CC may transmit a control message to ambientcommunication devices to inform the communication device determined asthe CE in operation 308.

The communication devices in the PCG may determine whether they arebeing carried by the user using various sensors. The smartwatch maydetermine whether the smartwatch is being worn by the user bydetermining whether the smartwatch contacts the user's skin or whetherthe heart beats through a contact sensor or a heartbeat sensor. Thesmart glasses may determine whether the smart glasses are being worn bythe user by determining the user's pupil movement or whether the smartglasses contact the user's skin through an eyeball recognition sensor orcontact sensor. The smart contact lens may determine whether the smartcontact lens is being worn by the user by determining whether the smartcontact lens contacts the user's eyeball using a blood sugar recognitionsensor. The smartphone may determine whether the smartphone is beingworn by the user by determining whether the user is on the move througha motion sensor. The smartphone may determine whether the smartphone isbeing carried by the user through a contact sensor or heartbeat sensoras well. Further, the smartphone may determine whether the smartphone isbeing carried by the user through whether the global positioning system(GPS) module of the smartphone is driven, through mobility obtainedthrough the GPS module, or through whether the smartphone had performedcommunication during a recent period.

Meanwhile, there may occur some situations where the once determined CCshould be changed in a particular event. For example, it may be the casethat the remaining battery life of the smartwatch currently operating asthe CC is reduced to a certain level (e.g., 5%) or less or the usertakes off the smartwatch or smart glasses operating as the CC. The othercommunication devices present in the PCG do not receive signals from theCC through the short-range communication link and thus may determinethat the CC is vacant. Thereafter, the other communication deviceshaving lost the CC may periodically perform determination as to whetherthey should be a new CC by determining whether there is a device with ahigher priority than themselves among approaching communication devices,as described above in connection with FIG. 2. As another example, theuser may arbitrarily select a CC to which to be changed using the userinterface (UI) of a communication device in the PCG. Communicationdevices available or unavailable in the PCG where the communicationdevice belongs or other accessible PCG are displayed on the UI in a formnoticeable to the user, and the user may select the CC from thedisplayed communication devices.

In an embodiment of the present disclosure, the proximity determinationstandard in a short-range communication scheme (e.g., Bluetooth) mayapply, as is, to determination of the proximity between communicationdevices (determination as to whether the devices are positioned within aproximate distance). For example, the communication devices maydetermine the proximity therebetween by comparing the strength of asignal used (detected) in the short-range communication link with athreshold.

Meanwhile, there may occur some situations where the once determined CEshould be changed in a particular event. For example, it may be the casethat the remaining battery life of the smartwatch currently operating asthe CE is reduced to a certain level (e.g., 5%) or less or the userleaves behind the smartphone operating as the CE and moves so that theproximity with the CE is deteriorated. Other communication devices(i.e., the CC) present in the PCG do not receive signals from the CEthrough the short-range communication link and thus may determine thatthe CC is vacant. Thereafter, the CC having lost the CE may determinethe communication device with the next highest priority among ambientcommunication devices as a new CE and may transmit, to the determinedcommunication device, a control message to instruct the determinedcommunication device to operate as the CE, as described above inconnection with FIG. 3. As another example, the user may arbitrarilyselect a CE to which to be changed using the UI of a communicationdevice in the PCG. Communication devices available or unavailable in thePCG where the communication device belongs or other accessible PCG aredisplayed on the UI in a form noticeable to the user, and the user mayselect the CE from the displayed communication devices.

Further, there may occur the situation where the determined CC and CEare simultaneously changed. For example, when the communication devicepresent in the PCG disconnects from the CE without prior notice nor doesthe communication device receive information on a new CE from the CC,the communication device may determine that the CC and the CE should besimultaneously changed. Thereafter, the communication device maydetermine whether the communication device should be a new CC asexemplified above in connection with FIG. 2. When the communicationdevice is determined to operate as the new CC, the communication device,as the new CC, may designate a new CE as exemplified in connection withFIG. 3. However, unless the communication device is determined tooperate as the new CC, the communication device may wait until thecommunication device receives a control message regarding thedetermination of a CE from a new CC. As another example, the user mayarbitrarily select a CC and CE, to which to be changed, using the UI ofa communication device in the PCG. Communication devices available orunavailable in the PCG where the communication device belongs or otheraccessible PCG are displayed on the UI in a form noticeable to the user,and the user may select the CC and CE from the displayed communicationdevices.

FIG. 4 illustrates a communication path to a cellular network, of a userwith a smartphone and a wearable communication device according to afirst embodiment of the present disclosure.

Referring to FIG. 4, the communication device operating as a CC mayenable a mobile communication connection from at least one of a firstcommunication device 402 and a second communication device 404 to anexternal network 420 based on a proximity between the firstcommunication device 402 and the second communication device 404. In theexample illustrated in FIG. 4, the first communication device 402 is asmartwatch, and the second communication device 404 is a smartphone.

When the first communication device 402 and the second communicationdevice 404 is positioned within a reach (i.e., a proximate distance) ofa short-range communication link 414 (e.g., Bluetooth, Wi-Fi Direct,Zigbee), the first communication device 402 playing a role as the CC mayperform control to disable a first link 410 between the firstcommunication device 402 and the network 420 and to enable a second link412 between the second communication device 404 and the network 420. Inthis case, as the second communication device 404 performs cellularcommunication, data required by the first communication device 402,among data obtained from the network 420, may be forwarded through athird link 414 to the first communication device 402. Accordingly, auser 400 may be served with a communication service of the network 420from the first communication device 402 through a path 424 passingthrough the third link 414, a short-range communication link, and theenabled second link 412. In such case, the second communication device404 becomes a CE.

When the first communication device 402 and the second communicationdevice 404 is positioned out of the reach (i.e., a proximate distance)of a short-range communication link 414, the first communication device402 playing a role as the CC may perform control to enable the firstlink 410 between the first communication device 402 and the network 420and to disable the second link 412 between the second communicationdevice 404 and the network 420. In this case, the user 400 may be servedwith a communication service of the network 420 from the firstcommunication device 402 through a path 422 passing through the enabledfirst link 410. In such case, the first communication device 402 becomesa CE.

Selectively, in a period (e.g., within a threshold time from the timewhen the short-range communication link has been lost) during which theshort-range communication link 414 may have a chance of being restoredalthough the first communication device 402 and the second communicationdevice 404 are positioned out of the reach of the short-rangecommunication link 414, the first communication device 402 playing arole as the CC may maintain the connection with the network 420 throughtwo long-range communication links by enabling the first link as well asby the second communication link being currently enabled. In such case,the first communication device 402 and the second communication device404 become CEs. The reason for simultaneously maintaining the twocommunication links during the threshold period is to prevent thephenomenon that the first communication device 402 and the secondcommunication device 404 are repetitively disabled/enabled due torestoration of the short-range communication link 414 within thethreshold period-so-called “ping-pong” phenomenon.

However, in a period (e.g., the threshold time after the short-rangecommunication link has been lost) during which the first communicationdevice 402 and the second communication device 404 are positioned out ofthe reach of the short-range communication link 414 and the short-rangecommunication link 414 has no chance of being restored, the firstcommunication device 402 playing a role as the CC may perform control todisable the second link 412 between the second communication device 404and the network 420 without maintaining the connection with the network420 through the two long-range communication links.

If the device carried by the user 400 is the first communication device402, the first communication device 402 would play a role as the CC.Selectively, the first communication device 402, a smartwatch, mayautomatically enable or maintain the cellular communication function ofthe first communication device 402 and disable the cellularcommunication function of the second communication device 404 withoutreceiving the user's separate manipulation.

On the other hand, if the device carried by the user 400 is the secondcommunication device 404, the second communication device 404 may play arole as the CC. Selectively, the second communication device 404, asmartphone, may enable the cellular communication function of the secondcommunication device 404 (i.e., the cellular communication function ofthe second communication device 404) and disable the cellularcommunication function of the first communication device 402 based onthe user's manipulation.

FIGS. 5A, 5B, and 5C illustrate a method in which two communicationdevices configure communication links with a network based on proximityaccording to a first embodiment of the present disclosure.

Referring to FIG. 5A, an operation of a first communication device 500operating in supplemental mode when the two communication devices arepositioned within a proximate distance is illustrated.

The supplemental mode is a mode in which the first communication device500 is connected with a cellular network through a proximate secondcommunication device, i.e., a mode in which the first communicationdevice 500 connects to the cellular network by interworking with othercommunication device.

When the first communication device 500 is determined to be positionedwithin a reach (i.e., a proximate distance) of a short-rangecommunication link with a second communication device 502 in operation510, the first communication device 500 may be determined to operate insupplemental mode in operation 515.

The second communication device 502 forms a long-range communicationlink with a network (NW) 504 and maintains the connected state (underthe control of a CC) in operation 525. In this case, the firstcommunication device 500 may operate as the CC, and the secondcommunication device 502 operates as a CE. The second communicationdevice 502 may forward, through the short-range communication link tothe first communication device 500, data required by the firstcommunication device 500 among data received from the network 504 inoperation 520.

Referring to FIG. 5B, an operation of the first communication device 500operating in stand-alone mode when the two communication devices arepositioned out of proximate distance is illustrated.

The stand-alone mode is a mode in which the first communication device500 independently connects to the cellular network without the aid ofother communication device.

For example, when the user leaves behind his smartphone being operatedas the CE, the smartwatch being worn by the user may be determined tooperate in stand-alone mode.

When the first communication device 500 determines that the secondcommunication device 502 is positioned out of the reach (i.e., theproximate distance) of the short-range communication link in operation530, the first communication device 500 may be determined to operate instand-alone mode in operation 535. The first communication device 500may perform a connection setup to form a long-range communication linkwith the network 504 (under the control of the CC) in operation 540. Inthis case, the first communication device 500 may simultaneously operateas a CC and a CE. The first communication device 500 may receive datathrough the long-range communication link established by the firstcommunication device 500 with the network 504.

Selectively, the network 504 may detect a mode change in the firstcommunication device 500 in operation 545. If the network 504 has beenconnected with the second communication device 502, the network 504 mayperform an operation to release the connection with the secondcommunication device 502 in operation 550. Alternatively, the connectionreleasing operation 550 may also be performed by the secondcommunication device 502 that has detected that the first communicationdevice 500 is positioned out of the proximate distance.

Referring to FIG. 5C, an operation of the first communication device 500operating in supplemental mode when the two communication devices arepositioned back within the proximate distance is illustrated.

For example, when the user is back and carries his smartphone, thesmartwatch being worn by the user may be determined to operate back insupplemental mode.

When the first communication device 500 determines that the secondcommunication device 502 is positioned back within the proximatedistance in operation 560, the first communication device 500 may bedetermined to operate back in supplemental mode in operation 565. Thesecond communication device 502 may perform a connection setup operationto form a long-range communication link with the network 504 (under thecontrol of the CC) in operation 570. In this case, the firstcommunication device 500 may operate as the CC, and the secondcommunication device 502 operates as the CE. The second communicationdevice 502 may forward, through the short-range communication link tothe first communication device 500, data required by the firstcommunication device 500 among data received from the network 504 inoperation 585.

Selectively, the network 504 may detect a mode change in the firstcommunication device 500 in operation 575. If the network 504 has beenconnected with the first communication device 500, the network 504 mayperform an operation to release the connection with the firstcommunication device 500 in operation 580. Alternatively, the connectionreleasing operation 580 may also be performed by the first communicationdevice 500 that has detected that the second communication device 502 ispositioned within the proximate distance.

The CC and CE described above in connection with the first embodimentmay also apply to wearable Internet of Things (TOT) gateways.

The wearable IoT means IoT applying between wearable communicationdevices. The wearable IoT gateway means a device that collects data froma group of IoT devices, transfers the data to a server over the Internetor distributes data received from the server over the Internet to theIoT devices. The wearable IoT may be denoted an IoT hub. For example, ahealth sensor unable to perform WAN communication and at least one otherdevice able to perform WAN communication may form one PCG. In this case,the CC (e.g., an IoT gateway) in the PCG selects one of WAN-communicabledevices as a CE and allows heat data (various data collected from ahuman body, such as blood pressure, body temperature, or heartbeat)collected by health sensors to be transferred to the CE. The healthsensors are devices that are attached or implanted in various parts of ahuman body to collect or transfer bio signals, and the health sensorscannot perform WAN communication but may communicate with the IoTgateway through a short-range communication link.

By way of example, the CC in the PCG may control the heath sensors todirectly transmit the health data to the CE through the short-rangecommunication link. As another example, the CC in the PCG may control aseparate collecting device to collect and store the health data from thehealth sensors and transmit the health data to the CE through theshort-range communication link. The CE in the PCG may transfer thereceived health data through long-range communication to a certainserver over the Internet, which manages the health data.

In this case, the CE in the PCG may play a role as an IoT gateway, andthe CC in the PCG may determine and manage a device to operate as an IoTgateway through the above-described method.

A method in which a communication device only capable of short-rangecommunication directly performs long-range communication with the aid ofa device capable of long-range communication is described below,according to a second embodiment of the present disclosure.

As described above, a peer device group (PDG) may be configured in thesame form as the PCG of FIG. 1. According to the second embodiment ofthe present disclosure, any communication device in the PCG may performcommunication with a network more efficiently by directly performinglong-range communication with the aid of other long-range communicablecommunication device. The communication device may be a communicationdevice incapable of independent cellular communication (e.g., LTE orHSPA).

Table 2 shows the communication capabilities of communication devicesconfiguring the PDG.

TABLE 2 short-range long-range communication communication (LRC) (SRC)LTE HSPA Wi-Fi Bluetooth smartphone O O O O smartwatch O X O O smartglasses X X O O health sensor X X X O smart pen X X X O

For example, the smart glasses in the PDG, although not equipped with along-range communication function, e.g., LTE or high speed packet access(HSPA), is equipped with a long-range communication function, e.g.,Wi-Fi. In this case, the smart glasses may be implemented to directlyperform long-range communication (e.g., Wi-Fi) using long-rangecommunication assistance information provided from the smartphone.

FIG. 6 illustrates a long-range communication method by a communicationdevice according to a second embodiment of the present disclosure.

Referring to FIG. 6, a first communication device 600 collectslong-range communication assistance information and provides theassistance information to a second communication device 602. Forexample, the first communication device 600 may be a smartphone with acellular communication function, e.g., LTE or HSPA.

The second communication device 602 may perform an operation related tothe LRC using the assistance information provided from the firstcommunication device 600. For example, the second communication device602 may be smart glasses with a Wi-Fi communication function. TheLRC-related operation may be an operation in which the secondcommunication device 602 directly performs LRC communication by usingshort-range communication and the assistance information.

A third communication device 604 may play a role to monitor the LRCcircumstance in the PDG and relay the assistance information from thefirst communication device 600 to the second communication device 602.The communication device playing the same role as the secondcommunication device 602 may be referred to as a PDG controller. Forexample, the third communication device 604 may be a communicationdevice, such as a smartwatch that is equipped with a short-rangecommunication function and has high priority of serving as the CC.

A method in which the second communication device 602 performs theLRC-related operation with the aid of the first communication device 600is described below with reference to FIG. 6.

The second communication device 602 transmits a request for LRCassistance information to the first communication device 600 with an LRCfunction. Selectively, there may be the third communication device 604as a PDG controller relaying the request for the LRC assistanceinformation. In this case, the second communication device 602 transmitsan LRC assistance information request to the third communication device604 in operation 610 and the third communication device 604 may transferthe LRC assistance information request to the first communication device600 in operation 612.

When receiving the LRC assistance information request from the secondcommunication device 602, the first communication device 600 collectsLRC assistance information using the LRC communication function inoperation 614.

The first communication device 600 transmits the collected LRCassistance information to the second communication device 602.Selectively, there may be the third communication device 604 as a PDGcontroller relaying the transfer of the LRC assistance information. Inthis case, the first communication device 600 transmits the LRCassistance information to the third communication device 604 inoperation 616 and the third communication device 604 may transfer theLRC assistance information to the second communication device 602 inoperation 618.

When receiving the LRC assistance information, the second communicationdevice 602 may perform an LRC-related operation using the LRC assistanceinformation in operation 620.

Table 3 describes examples of the LRC assistance information transferredfrom the first communication device 600 to the second communicationdevice 602 and an example of the LRC-related operation performed by thesecond communication device 602.

TABLE 3 first second third communication communication communication LRCassistance operation of device device device LRC information scenariosecond device smartphone smart glasses smartwatch Wi- discovery (1)necessity quick Wi-Fi Fi information: for smart access using informationrelating glasses to do discovery to AP performing Wi-Fi informationcommunication communication through smartphone occurs Wi-Fi (SSID,channel information, and the like) smartphone smart glasses smartwatchWi- SIB 17, ANDSF (2) necessity initiate Wi-Fi Fi information: for smartsearch SSID list, offloading glasses to do policy, Wi-Fi access Wi-Fiauthentication communication information occurs smartphone smart glassessmartwatch Wi- whether Wi-Fi (3) necessity initiate Wi-Fi Fi signal isdetected for smart search detected Wi-Fi AP glasses to do informationWi-Fi communication occurs smartphone smart glasses smartwatch LTE firstaccess (4) necessity quick LTE access information LTE for smart usingaccess serving cell glasses to do information information system LTEinformation communication occurs smartphone smart glasses smartwatch LTEsecond access (5) necessity First device information security for smartterminates LTE parameter, C-RNTI, glasses to do communication, radioconfiguration, LTE second device S-TMSI communication initiates LTEswitching communication. occurs Use credential information provided uponinitiation of LTE communication. AKA/security setup process omitted

When the second communication device happens to have necessity todirectly perform Wi-Fi communication (scenario (1) in Table 3), the LRCassistance information received by the second communication device fromthe first communication device may contain discovery information. Forexample, the discovery information may be information related to anaccess point (AP) performing communication through the Wi-Fi function ofthe smartphone (first communication device), i.e., SSID) or channelinformation. The second communication device may perform long-rangecommunication by quick Wi-Fi access using the discovery information.

Alternatively, when the second communication device happens to havenecessity to directly perform Wi-Fi communication (scenario (2) in Table3), the LRC assistance information received by the second communicationdevice from the first communication device may contain systeminformation block (SIB) 17 information. For example, the SIB 17information may contain an SSID list, an offloading policy, and Wi-Fiauthentication information. The second communication device may initiatea search for a Wi-Fi channel which the second communication device is toaccess using the SIB 17 information. The SIB 17 information is systeminformation providing the Wi-Fi-related information owned by the networkprovider and may follow what has been set forth in 3GPP standard TS36.331. The offloading policy is information designating what traffic isto be transmitted through Wi-Fi and may follow what has been set forthin, e.g., 3GPP standard TS 36.331.

Alternatively, when the second communication device has necessity todirectly perform Wi-Fi communication (scenario (3) in Table 3), the LRCassistance information received by the second communication device fromthe first communication device may contain information as to whether aWi-Fi signal is detected. For example, the information as to whether aWi-Fi signal is detected may contain detected Wi-Fi AP information(e.g., SSID, extended SSID (ESSID), and channel number of Wi-Fi AP). Thesecond communication device may initiate a search for a Wi-Fi channelwhich the second communication device is to access using the detectedWi-Fi AP information. The SSID, ESSID, Wi-Fi channel number, or Wi-Fiaccess authentication information follows what is set forth in the IEEE802.11 standard.

Alternatively, when the second communication device has necessity todirectly perform LTE communication (scenario (4) in Table 3), the LRCassistance information received by the second communication device fromthe first communication device may contain first access information. Thefirst access information is all or some of the information necessary forthe second communication device to access an LTE network and may containinformation on the LTE serving cell and system information. The secondcommunication device may quickly access the LTE network using the firstaccess information. Specifically, the first access information maycontain information related to the current serving cell of the firstcommunication device, e.g., frequency information, e.g., E-UTRA absoluteradio frequency channel number (EARFCN), a cell identifier, e.g.,physical cell identifier (PCID), downlink feedback channel configurationinformation of serving cell, current system frame number (SFN) ofserving cell, and random access channel configuration information ofserving cell. The definitions or uses of the examples of the firstaccess information may follow what has been set forth in TS 36.331.

Alternatively, when the second communication device has necessity forLTE communication switching (scenario (5) in Table 3), the LRCassistance information received by the second communication device fromthe first communication device may contain second access information.The second access information is all or some of the informationnecessary for the second communication device to access an LTE networkand may contain, e.g., security parameter, cell-radio network temporaryidentifier (C-RNTI), radio configuration information, and SAE-temporarymobile subscriber identity (S-TMSI). In this case, the firstcommunication device may terminate the LTE communication, and the secondcommunication device may directly initiate LTE communication. The secondcommunication device may omit the authentication and key agreement (AKA)or security setup process in the process of initiating the LTEcommunication using the security parameter (e.g., credentialinformation). Accordingly, the second communication device may morequickly perform the switching process. Specifically, the securityparameter may be information on the security key currently in use orinformation on the counter to be used in scrambling/descrambling. Theradio configuration information may be, e.g., physical layerconfiguration information, media access control (MAC) configurationinformation, or radio bearer configuration information currentlyconfigured in the first communication device.

The PDG controller regularly determines the state of the communicationdevices belonging to the PDG and enables at least one CE (thecommunication device performing LRC in the PDG and providing LRCassistance information) in the PDG to properly work all the time basedon the user's preference or battery condition. In some cases, the PDGcontroller may increase the data rate by operating two or more CEs. Whenthe PDG controller operates two or more CEs, LRC assistance informationavailable for one CE may be shared with other CEs, thus enhancing theefficiency of the LRC-related operation.

The user's preference related with the number of CEs in the PDG may beinput through the interface of one of the communication devicesbelonging to the PDG or directly determined by the PDG controllerconsidering the condition information, for example. For example, if thecommunication devices in the PDG are under poor battery conditions, thecommunication devices may be preferable to operate only one CE. Or, if aservice creating heavy traffic is initiated or occurrence of heavytraffic is observed for a certain period or more, two or more CEs in thePDG may be operated. In this case, the plurality of CEs may use the sameor different long-range communication techniques.

Now described is a method in which a communication device is automatedto periodically transmit device-to-device (D2D) discovery messagesaccording to a third embodiment of the present disclosure.

When a communication device transmits a particular call (e.g., anemergency call, such as a 911 call), the communication device may beimportant to transmit a signal (i.e., a discovery signal) for informingthe position of the communication device. Further, from a perspective ofthe nature of emergency, the dispatch of a discovery signal needs to beblocked off, as possible, from manipulation or interference by the userusing the communication device. For example, in such cases where theemergency call is abruptly disconnected, the user cannot speak out, orthe user cannot manipulate the communication device, it is difficult toexpect the user's manipulation for transmitting out a discovery signal.

In some cases, the communication device, even without connection (e.g.,a radio resource control (RRC) connection) with a base station, needs toinform the position of the communication device around by transmitting adiscovery signal.

The communication device, when positioned indoors, is unable to doglobal positioning system (GSP) transmission. Accordingly, the GPScannot be an alternative available for transmission of positioninformation upon emergency, and neither can WLANs with small signaltransmission coverage. Meanwhile, standardization of the D2D discoveryfunction is being researched in the recent LTE standard, Rel-12.

The present disclosure proposes a method in which a communication deviceautomatically performs periodic transmission of D2D discover messagesupon transmitting a particular call or upon triggering an operation oftransmitting data or an operation of driving a particular application.

FIG. 7 illustrates a procedure in which a communication device (UE)communicates with a base station and a ProSe function to transmit adiscovery signal according to a third embodiment of the presentdisclosure.

Referring to FIG. 7, a communication device (UE) 700 transmits a ProSediscovery authentication/registration request (REQ) to a ProSe function710 over a network in operation 720. The communication device 700 is adevice, such as a UE, supportive of a D2D discovery communicationfunction. The ProSe function 710 may set up parameter values related toauthentication/registration for a D2D discovery user (or device). Forexample, the ProSe function 710 may allocate a ProSe discovery ID to becontained in the transmitted discovery signal.

When receiving the ProSe discovery authentication/registration request720, the ProSe function 710 transmits a ProSe discoveryauthentication/registration response (RES) to the communication device700 in operation 725. The ProSe function 710 may inform, through theProSe discovery authentication/registration response message, whetherthe ProSe discovery authentication/registration of the communicationdevice 700 or user succeeds or fails. The ProSe function 710 mayallocate a discovery ID to be transmitted by the communication device700 or user and may include the same in the ProSe discoveryauthentication/registration response message. The discovery ID may be anID for identifying the use of discovery (e.g., for emergency oradvertisement), the user of the communication device 700, thecommunication device 700, or an application operating on thecommunication device 700. Selectively, the ProSe function 710 mayinclude a destination phone number of the call along with the discoveryID for call dispatch, include the destination address of the data alongwith the discovery ID for data transmission, and in the case of drivingan application, include the application and a discovery ID mapped withthe application.

At any time, a base station 705 (e.g., an eNB in the LTE system) overthe network may transfer ProSe discovery resource configurationinformation to be used by the communication device 700 for discoverytransmission by broadcasting system information blocks (SIBs) to the UEsin the cell in operation 730. The communication device 700 may obtainthe resource configuration information to be used when transmitting aProSe discovery message in the cell by receiving the SIB 730 broadcastin the cell. For example, if the resource configuration information isinformation related to a radio resource pool, the resource configurationinformation may indicate the position of the radio resource pool in thetime domain and frequency domain.

When the communication device 700 triggers dispatch of a particularcall, triggers data transmission, or drives a particular application inoperation 735 by the user's manipulation or a preset condition, thecommunication device 700 may initiate an operation for discoverytransmission. For example, the particular call triggering the discoverysignal transmission may be replaced with other type of user input. Forexample, the communication device 700 may also trigger the operation ofautomatically transmitting the discovery signal by an operation oftransmitting data, an operation of driving a particular application, oran operation of pressing an emergency button provided at a position ofthe communication device 700 or an operation of pressing an emergencybutton output at a position on the screen of the communication device.

Selectively, the communication device 700 may establish an RRCconnection with the base station 705 in operation 740. If thecommunication device 700 establishes the RRC connection, the basestation 705 happens to be able to communicate a UE-dedicated controlmessage for the UE.

Selectively, the communication device 700 may configure a radio bearer(RB) for transmission of user data through an RRC connectionreconfiguration procedure with the base station 705 in operation 750. Inthis case, the configuration information of the radio bearer may bedelivered to the communication device 700, and the communication device700 may allocate dedicated radio resources to be used for ProSediscovery transmission.

The communication device 700 may transmit a call, transmit user data, ordrive a particular application in operation 760.

The communication device 700 transmits a ProSe discovery signalincluding a discovery ID corresponding (mapped) to the operationtriggered in operation 735 in operation 770(a). For example, if the callhas been triggered with a particular number preset by the user of thecommunication device 700, the ProSe function 710, or communicationprovider, if the data transmission has been triggered with a destinationaddress preset by the user, the ProSe function 710, or the communicationprovider, or if the application corresponds to an application preset bythe user, the ProSe function 710, or the communication provider, thecommunication device 700 periodically transmits discovery signalsincluding the discovery ID mapped with the particular number ordestination address in operations 770(a), 770(b), and 770(c).

The power control for periodic transmission of the discovery message maybe operated depending on various alternatives. A first alternative is amethod in which the power of discovery transmission is divided into Noperations (N>1), and different amounts of transmission power areconfigured for transmission periods, respectively. As an example, thecommunication device 700 may enable the discovery signal to reachvarious arrival ranges by randomizing the discovery transmission power.This case is advantageous in that the position information of thecommunication device 700 may be informed in various radii of coverage. Asecond alternative is a method in which, upon transmission, thediscovery transmission power at each transmission period is reduced to aparticular threshold or less. By way of example, the position of thecommunication device 700 may be informed even in a very small range byminimizing the discovery transmission power of the communication device700 and resultantly minimize the UE's power consumption. A thirdalternative is a method that determines whether the communication device700 receives a GPS signal in determining the discovery transmissionpower at each transmission period. For example, when a GPS signal isreceived, the discovery transmission power may be minimized, and if noGPS signal is received, a discovery signal may be transmitted with acertain amount of power or more. Which one of the above alternatives isto be chosen by the communication device 700 may be determined by theuser's prior settings or settings made when the discovery service isregistered.

A radio resource used by the communication device 700 to transmit theProSe discovery may be allocated through the SIB 730 broadcast form thebase station 705 or the RRC connection reconfiguration procedure 750. Inother words, if the communication device 700 has been allocated adedicated radio resource for discovery transmission in the RRCconnection reconfiguration procedure 750, the communication device 700may transmit the discovery signal through the transmitted radioresource, and if the communication device 700 has received informationon the radio resource pool from the SIB 730, the communication device700 may select a resource to be used from the radio resource pool andtransmit the discovery signal through the selected resource.

It should be noted that the ProSe discovery transmission operation 770has no cause-and-result relation, in order, with the call dispatch, datatransmission, or application driving operation 760. In other words, oneof operations 760 and 770 may be performed earlier than the other, andthe operations may be performed at the same time.

Meanwhile, the user may abort the periodic discovery transmission inoperations 770(a), 770(b), and 770(c) by manipulating the communicationdevice 700 through a particular user interface or expiration of aparticular timer. In this case, the communication device 700 may requirea particular user input (e.g., a password) for user identification inorder to identify whether the abortion of discovery transmission isvalid.

Further, after the communication device 700 has triggered the operationfor discovery signal transmission, other wearable device, as carried bythe user, than the communication device 700 may periodically transmitD2D discovery signals as well. For example, when the battery capacity ofthe smartphone transmitting discovery signals is reduced to a certainlevel or less, other wearable communication device of the user carryingthe smartphone may also transmit the discovery signal. An example of thewearable device may be a bracelet-style communication device or asmartwatch.

In the instant embodiment of the present disclosure, the user may applyand subscribe to a service for the discovery signal transmission method,or the user may set up an automatic discovery message transmittingfunction in his communication device.

FIG. 8 illustrates a discovery signal transmission operation by acommunication device according to a third embodiment of the presentdisclosure.

Referring to FIG. 8, the communication device (e.g., a UE) configures orstores a destination phone number of a call triggering the transmissionof a discovery signal, a destination address of data transmission, orapplication information in operation 800. The configuring or storingoperation by the communication device may be performed by, e.g., theuser's input, the communication provider's settings, a command from theProSe function, and the like.

The communication device performs a particular call, data transmission,or application driving in operation 802. The particular call, datatransmission, or application driving may be performed, for example, bythe user's input or when a certain condition is met.

The communication device determines whether the destination phone numberof the call, the destination address of the data transmission, or thedriven application is contained in preset (stored) information inoperation 806.

As a result of the determination 806, when the destination phone numberof the call, the destination address of the data transmission, and thedriven application are not included in the preset (stored) information,the communication device transmits a call, transmits data, or executesan application without an additional operation in operation 818. As aresult of the determination 806, when the destination phone number ofthe call, the destination address of the data transmission, or thedriven application is included in the preset (stored) information, thecommunication device determines if there is a dedicated radio resourceallocated by the base station for discovery signal transmission inoperation 808.

If it is determined in operation 808 that there is a dedicated radioresource allocated by the base station for discovery signaltransmission, the communication device transmits, through the dedicatedradio resource, a discovery signal including a discovery ID mapped tothe destination phone number of the call, the destination address of thedata transmission, or the driven application in operation 810, andtransmits the call, transmits the data, or executes the application inoperation 818. If it is determined in operation 808 that there is nodedicated radio resource allocated by the base station for discoverysignal transmission, the communication device determines if the SIBbroadcast from the base station contains information regarding a radioresource pool for discovery signal transmission in operation 812.

If it is determined in operation 812 that the SIB contains theinformation regarding the radio resource pool for discovery signaltransmission, the communication device selects a resource to be used fordiscovery signal transmission from the radio resource pool, transmits,through the selected resource, a discovery signal including a discoveryID mapped to the destination phone number of the call, the destinationaddress of the data transmission, or the driven application in operation814, and transmits the call, transmits the data, or executes theapplication in operation 818. If it is determined in operation 812 thatthe SIB contains no information regarding the radio resource pool fordiscovery signal transmission, the communication device transmits arequest for a radio resource to be used for discovery signaltransmission (e.g., through an RRC connection) to the base station inoperation 816 and may repeat operation 808. In this case, selectively,the communication device may transmit the call, transmit the data, orexecute the application in operation 818 without determining whether thebase station responds to the request transmitted in operation 816 (808).

Although in the example illustrated in FIG. 8 the operation 808 ofdetermining whether there is an allocated dedicated radio resource isperformed earlier than the operation 812 of determining the radioresource pool through the SIB, the determining operations may bereversed in order.

FIG. 9 illustrates a configuration of a communication device accordingto an embodiment of the present disclosure.

Referring to FIG. 9, a communication device 900 may include acommunication unit (or transmission/reception unit) 905 communicatingsignals with other communication device or an entity in a network and acontroller 910 controlling all of the operations performed by thecommunication device 900. It may be appreciated that all of theoperations of the communication device or UE described above inconnection with the first to third embodiments of the present disclosureare performed under the control of the controller 910. However, thecontroller 910 and the communication unit 905 are not necessarilyimplemented as separate devices, respectively, but may be implemented ina single configuration unit in the form of, e.g., a single chip.

It should be noted that the system configuration, various methods fordetermining CC/CE, signal flow between communication devices,communication flow between the communication device and the networkentity, various methods for transmitting discovery signals by thecommunication device, and configuration of the communication deviceillustrated in FIGS. 1 to 9 as examples are not intended to limit thescope of the present disclosure. For example, the messages, signals, oroperations in the constituent units described in connection with FIGS. 1to 9 should not be interpreted as essential components to practice thepresent disclosure, and only some of the messages, signals, operations,or components may be included, or changes in order may be made to theoperations without affecting the essence of the present disclosure.

The above-described operations may be realized by equipping a memorydevice retaining their corresponding codes in a communication device ora function in a communication system or in any constituent unit in abase station. For example, the controller in the entity, function,communication device, or the base station may execute theabove-described operations by reading and executing the program codesstored in the memory device by a processor or central processing unit(CPU).

As described herein, various constituent units or modules in the entity,communication device, or base station may be operated using a hardwarecircuit, e.g., a complementary metal oxide semiconductor-based logiccircuit, firmware, software, and/or using a hardware circuit, such as acombination of hardware, firmware, and/or software embedded in amachine-readable medium. As an example, various electric structures andmethods may be executed using electric circuits, such as transistors,logic gates, or ASICs.

While the present disclosure has been shown and described with referenceto various embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present disclosure asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method for communicating by a secondcommunication device in a wireless communication system, the methodcomprising: transmitting a request for long-range communication supportinformation to a first communication device through a short-rangecommunication link; receiving the long-range communication supportinformation from the first communication device; and accessing to aninternet using the long-range communication support information receivedfrom the first communication device, wherein the long-rangecommunication support information includes at least one of Wi-Fi accesspoint (Wi-Fi AP) access information or long-term evolution (LTE) accessinformation, wherein the LTE access information includes a securityparameter of the first communication device and at least one of acell-radio network temporary identifier (C-RNTI) of the firstcommunication device, radio configuration information of the firstcommunication device, or a system architecture evolution (SAE)-temporarymobile subscriber identity (S-TMSI) of the first communication device,and wherein the security parameter includes information on a securitykey currently in use by the first communication device or information ona counter to be used by the first communication device in scrambling ordescrambling.
 2. The method of claim 1, wherein the LTE accessinformation further includes information on a LTE serving cell of thefirst communication device to access to the internet.
 3. The method ofclaim 2, wherein the information on the LTE serving cell includes atleast one of an evolved universal mobile telecommunications system(UMTS) terrestrial radio access (E-UTRA) absolute radio frequencychannel number (EARFCN), a physical cell identifier (PCID) of the LTEserving cell, downlink feedback channel configuration information of theLTE serving cell, a current system frame number (SFN) of the LTE servingcell, or random access channel configuration information of the LTEserving cell.
 4. The method of claim 1, wherein the radio configurationinformation includes at least one of physical layer configurationinformation, media access control (MAC) configuration information, orradio bearer configuration information currently configured in the firstcommunication device.
 5. The method of claim 1, wherein the short-rangecommunication link comprises a Bluetooth communication link or a Wi-Ficommunication link.
 6. The method of claim 1, wherein the secondcommunication device comprises a wearable communication device.
 7. Asecond communication device in a wireless communication system, thesecond communication device comprising: at least one processorconfigured to: transmit a request for long-range communication supportinformation to a first communication device through a short-rangecommunication link, receive the long-range communication supportinformation from the first communication device, and access to aninternet using the long-range communication support information receivedfrom the first communication device; and a communication unit configuredto communicate data through the short-range communication link under thecontrol of the at least one processor, wherein the long-rangecommunication support information includes at least one of Wi-Fi accesspoint (AP) access information or long-term evolution (LTE) accessinformation, wherein the LTE access information includes a securityparameter of the first communication device and at least one of acell-radio network temporary identifier (C-RNTI) of the firstcommunication device, radio configuration information of the firstcommunication device, or a system architecture evolution (SAE)-temporarymobile subscriber identity (S-TMSI) of the first communication device,and wherein the security parameter includes information on a securitykey currently in use by the first communication device or information ona counter to be used by the first communication device in scrambling ordescrambling.
 8. The second communication device of claim 7, wherein theLTE access information further includes information on a LTE servingcell of the first communication device to access to the internet.
 9. Thesecond communication device of claim 8, wherein the information on theLTE serving cell includes at least one of an evolved universal mobiletelecommunications system (UMTS) terrestrial radio access (E-UTRA)absolute radio frequency channel number (EARFCN), a physical cellidentifier (PCID) of the LTE serving cell, downlink feedback channelconfiguration information of the LTE serving cell, a current systemframe number (SFN) of the LTE serving cell, or random access channelconfiguration information of the LTE serving cell.
 10. The secondcommunication device of claim 7, wherein the radio configurationinformation includes at least one of physical layer configurationinformation, media access control (MAC) configuration information, orradio bearer configuration information currently configured in the firstcommunication device.
 11. The second communication device of claim 7,wherein the short-range communication link comprises a Bluetoothcommunication link or a Wi-Fi communication link.
 12. The secondcommunication device of claim 7, wherein the second communication devicecomprises a wearable communication device.
 13. A first communicationdevice in a wireless communication system, the first communicationdevice comprising: at least one processor configured to: receive arequest for long-range communication support information from a secondcommunication device through a short-range communication link, transmitthe long-range communication support information to the secondcommunication device, and relay an access from the second communicationdevice to an internet, using the long-range communication supportinformation transmitted to the first communication device; and acommunication unit configured to communicate data through theshort-range communication link under the control of the at least oneprocessor, wherein the long-range communication support informationincludes at least one of Wi-Fi access point (AP) access information orlong-term evolution (LTE) access information, wherein the LTE accessinformation includes a security parameter of the first communicationdevice and at least one of a cell-radio network temporary identifier(C-RNTI) of the first communication device, radio configurationinformation of the first communication device, or a system architectureevolution (SAE)-temporary mobile subscriber identity (S-TMSI) of thefirst communication device, and wherein the security parameter includesinformation on a security key currently in use by the firstcommunication device or information on a counter to be used by the firstcommunication device in scrambling or descrambling.
 14. The firstcommunication device of claim 13, wherein the LTE access informationfurther includes information on a LTE serving cell of the firstcommunication device to access to the internet.
 15. The firstcommunication device of claim 14, wherein the information on the LTEserving cell includes at least one of an evolved universal mobiletelecommunications system (UMTS) terrestrial radio access (E-UTRA)absolute radio frequency channel number (EARFCN), a physical cellidentifier (PCID) of the LTE serving cell, downlink feedback channelconfiguration information of the LTE serving cell, a current systemframe number (SFN) of the LTE serving cell, or random access channelconfiguration information of the LTE serving cell.